Re: BUG: fork do not copy /proc/<PID>/cmdline permissions

From: Richard B. Johnson
Date: Thu Apr 22 2004 - 15:38:04 EST

On Thu, 22 Apr 2004, Agri wrote:

> I expected from fork to make a rather complete copy of a process,
> but it does not copy /proc/<PID>/cmdline access permissions.
> Therefore, the only way (at least i know) to hide all args of
> processes is to start every program within shell script:
> bash -c 'chmod /proc/$$/cmdline; exec userprogramm ...'
> Tested on 2.6.5.
> Agri

Huh? /proc/$PID/cmdline doesn't exist until after a task is
created. What you did was create a task, change whatever
is in proc, then exec (which doesn't change the PID).

How would you expect fork() to know that you wanted to
do this? The permissions in /proc are file permissions.
They have nothing to do with a task.

Also, any task can read its own command-line without using
/proc at all.

Dick Johnson
Penguin : Linux version 2.4.26 on an i686 machine (5557.45 BogoMips).
Note 96.31% of all statistics are fiction.

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